Yesterday found in an antique shop a Atwater Kent 47 radio with matching F4 speaker. This is my first Atwater Kent Radio. This radio is quite heavy and it looks like it has 4 RF stages. The radio has 9 tubes. Any opinions and issues I should be concerned about for this radio and for the speaker? It looks like a small amount of tar has leaked out from the power transformer can and onto the label that lists the tubes. I don't know if this is a concern or not. I have not opened the transformer lid yet.

Here are some pictures:
http://i233.photobucket.com/albums/ee270/johnkrr/Atwater_Kent_47_1.jpg
http://i233.photobucket.com/albums/ee270/johnkrr/Atwater_Kent_47_4.jpg
http://i233.photobucket.com/albums/ee270/johnkrr/Atwater_Kent_47_5.jpg

John K.

Mind if I make them so that there is no opening of a link is involved?







Nice! I like the speaker too!

Nice find !

Interestingly I was just yesterday at Plant City Fl antique thingie and a guy there had some radios. He said he also has a green metal AK with the original speaker for sale at his house so I plan to go see his next week maybe.

Yours looks nice and clean inside. In case you did not know, according to the AK history book, the medalion on your radio used real 24K gold plating. They used to melt it at the factory and use it in the plating process somehow.

Bruce

The Model 47 uses the F-2 speaker, not the F-4. The F-2 has a 1700-ohm field coil, while the F-4 field coil is 1100 ohms. The F-4 was designed for the Model 55 and Model 60 radios. It might work with the 47 but I expect your B+ will be on the high side.

A list of all the earlier sets and speakers is on my site here http://www.atwaterkent.info/TechData/Im ... 32_024.gif

If you need a schematic, I did a modern one last April, here http://www.atwaterkent.info/TechData/Dr ... 500sch.pdf

Leigh,

Thanks for the information. I know nothing about Atwater Kent Radios and so this gives me a reason to research them a bit. I will check out your website. Do you have info on your website regarding the F2 and F4 speakers?

I assume that I could add a series resistor to make the resistance what is should be. Any clue as to the inductance difference between the 2 speakers? Assuming the iductance is 30% less I could increase the capacitance of the second capacitor by 30% to compensate if needed to reduce the power supply ripple.

John K.

Hi John

You won't have a problem with hum. The radio has a filter choke besides the speaker field. The field acts as a second choke.

Not as important to have the proper speaker with a Model 47. The Model 55 uses the choke to set bias on output tubes. Your speaker should have a 4 pin plug, a little smaller than 80 base. It plugs in by the back 71A and will work with your radio without adding resistance. Like Leigh mentioned, voltage will be higher but operates ok.

Your 47 is in great shape. Most are rusty inside.

Hi John,

I have no info posted on either of those speakers. I will have to dig through the original service manuals to see if anything was published. I don't think so. All of the radio service lit that AK published is on the site, along with most Rider pages covering AK radios.

Unfortunately, AK did not release any technical information for their products (neither did most other manufacturers). I would like to make some measurements and add the inductance info at some point, but have not had an opportunity to do so.

As Norm said, you should not have a hum problem. If you do, increase the output filter cap by some nominal amount.

Leigh and Norm,

Thanks for the information. Leigh, you have a great website! Thanks for providing all this information. It will make the restoration much easier. Your schematics are easier to follow compared to the older ones. I have about 3 radio's ahead of this one in the restoration que, so I have a few weeks to research info on the radio and speaker.

I searched through the forums here and I don't see many references to this particular radio, nor for the F4 speaker. Not a popular model perhaps? Looking at the schematic the restoration should be straight forward assuming the power transformer is good.

John K.

Hi John,

Au contraire, mon amis (sorry, I don't speak Franzuzisch )

The F-4 was probably the most popular AK speaker of that type. It was used in the Model 55 and Model 60 radios, which were extremely popular. There is an external version in a cylindrical housing, like the one in your photos. The more common version mounted inside the radio cabinet and had no housing of its own.

The Model 47, being at the high-performance end of the product line, was sold in lower numbers than similar less expensive models. The extra RF stage was an advantage only in fringe reception areas, or for people who could not erect a proper antenna for whatever reason.

And thanks for the kind words. Hope the info helps. Good luck with the restoration.

Hi,
I've got a Model 47 (no matching speaker yet) and it's a real performer. On a 150 foot long wire it will hear anything worth hearing, and it sounds pretty good on a decent speaker to boot! Excellent radio.

Wally